This application claims the priority of PCT International Patent Application No. PCT/EP99/03737, filed May 29, 1999 (29.05.99) and German patent document 198 25 102.5, filed Jun. 5, 1998 (05.06.98), the disclosure of which is expressly incorporated by reference herein.
The invention relates to a process for making a compact catalytic reactor.
Such compact catalytic reactors, so-called micro-reactors, comprise individual thin, finely structured plates or sheets, in which the structuring provides fine flow channels for the distribution of the required media. The sheets are stacked one on top of the other and are provided with bottom and top plates as well as with supply and discharge ducts for the media, so that a compact component is produced. The sheets are subsequently joined together in a gastight manner, preferably by diffusion welding. International patent document WO 88/06941 discloses, for example, a micro heat exchanger of microstructured sheets, which is joined together by soldering.
It is an object of the invention to provide a simple and inexpensive process for making a compact catalytic reactor of this type.
This and other objects and advantages are achieved by the manufacturing according to the invention, which provides a compact catalytic reactor with adequate leak tightness and mechanical strength. Since a layer of solder is provided on all the plates, at least in the edge region, neighboring plates are connected to one another in a gastight manner by the soldering operation, at least in this edge region, so that closed-off reaction or heat-transfer spaces form between respective neighboring plates. At the same time, a layer of solder is not introduced in the regions of the plates in which catalyst material is provided. As a result, damage to the catalyst material by the solder material can be avoided.
The strength in the region of the plates which is provided with catalyst is established exclusively by mechanical contact. If, in addition, all the plates which have no catalyst material are provided completely with a layer of solder, soldered connections are also produced in the central regions of these plates, so that the mechanical strength of the reactor can be further improved.
The bending up of the edge regions allows the plates to be positioned in a simple way during stacking one on top of the other and to be fixed during the soldering operation. At the same time, leak tightness is improved.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.